Optical system for a fresnel lens light, especially for a spotlight or floodlight

摘要

The optical system for the Fresnel lens light has an ellipsoidal reflector (1), a light source (2) and a Fresnel lens (3). The distance (a) between the Fresnel lens (3) and the reflector (1) is changeable but is related to the changeable distance (b) between the light source (2) and the reflector (1) so that the aperture angle of the propagated light beam is variable but illumination intensity of the propagated light is maintained uniform. Surfaces of the at least one Fresnel lens and/or the reflector can be structured to provide more uniform illumination of a given area. The optical system is useful for lights for film, stage, studio and photography.